For most small businesses, this decision comes down to one question: are you already paying for Microsoft 365? If yes, Teams is already in your subscription and the marginal cost is zero. If no, you're choosing between two paid products, and Slack usually wins on interface and integrations. The rest of this comparison fills in the details that matter past that starting point.
The stakes are real: 58% of Americans now have the opportunity to work from home at least part of the time (McKinsey Global Institute, 2022), which means communication tools aren't just a convenience — they're where a lot of actual work gets coordinated.
Quick comparison
| Feature | Microsoft Teams | Slack |
|---|---|---|
| Starting price | Free plan; included with Microsoft 365 (~$6/user/mo) | Free plan; Pro ~$7.25/user/mo |
| Free plan limits | Limited storage, 60-min meeting cap | 90-day message history, 10 integrations |
| Microsoft 365 integration | Deep — Word, Excel, SharePoint, Outlook | Available via connectors, not native |
| Third-party integrations | 700+ | 2,600+ |
| Video conferencing | Strong — up to 1,000 participants | Basic on free; Huddles on paid |
| Interface | Feature-dense, steeper learning curve | Cleaner, faster to navigate |
| Search | Decent across messages and files | Better for message search |
| Best for | Microsoft 365 shops, larger teams | Multi-tool stacks, async teams, startups |
Microsoft Teams
Teams is built to live inside the Microsoft 365 ecosystem. If your team already uses Outlook, SharePoint, Word, and Excel, Teams connects everything. You can open a Word document in a Teams channel, co-edit it in real time, schedule a meeting in Outlook from the same interface, and store files in SharePoint without copying anything manually. For businesses invested in Microsoft's stack, that integration removes a lot of the friction that comes with juggling separate tools.
Teams has scaled to 320 million monthly active users as of 2023 (Microsoft Annual Report, 2023), and 85% of Fortune 500 companies use it (Microsoft, 2023). That footprint matters practically: external partners, vendors, and clients are likely already on it, which smooths guest access and cross-org calls.
Video conferencing is one of Teams' genuine strengths. The free plan caps meetings at 60 minutes for groups, but paid plans support up to 1,000 participants with recording, transcription, and meeting notes. For IT and MSP businesses or accounting firms that run regular client calls, Teams' meeting quality is solid and doesn't require adding Zoom separately.
The interface is the main complaint. Teams packs a lot of features into the UI and it takes time to learn where things live. New users often find it harder to navigate than Slack at first. This matters less for teams with IT support to onboard people; it matters more for small businesses where everyone is self-sufficient.
Limitations to know:
- Interface is more complex than Slack — higher initial learning curve
- Third-party integration library (700+) is smaller than Slack's (2,600+)
- Free plan limits meetings to 60 minutes for groups and storage to 5GB per user
- Less useful if your stack is primarily non-Microsoft tools
Slack
Slack's main advantage is integration breadth. With over 2,600 integrations, it connects to more tools than Teams — including HubSpot, Salesforce, Jira, GitHub, PandaDoc, Zapier, and most CRM and project management platforms. For businesses running a mixed stack of best-in-class tools rather than an all-Microsoft setup, Slack fits better. (Slack was acquired by Salesforce in 2021 for $27.7 billion (Salesforce, 2021), which deepened the Salesforce CRM integration in particular.)
Slack reached 38.8 million daily active users as of 2023 (Salesforce/Slack, 2023) — a smaller footprint than Teams overall, but concentrated in tech, agencies, and multi-tool environments where Slack's integration breadth is the selling point.
The interface is cleaner and faster to navigate. Channel organization is more intuitive, search works well for finding past messages, and the mobile app is consistently better-reviewed than Teams' mobile experience. For remote or async teams where the tool needs to stay out of the way and just work, Slack tends to generate less frustration day-to-day.
The free plan's limitations are real: 90-day message history and only 10 integrations. For a small team just getting started those limits are manageable. Past that, the Pro plan at ~$7.25/user/month removes both caps. Slack Connect lets you communicate with external clients and vendors in shared channels without email, which is useful for businesses with ongoing client relationships.
Limitations to know:
- Free plan limits message history to 90 days — older messages disappear
- Video conferencing is basic compared to Teams; Huddles work for quick calls but not large meetings
- No native Microsoft 365 integration — SharePoint and Outlook connections require extra setup
- Can become noisy without good channel discipline — notification management matters
Teams wins on video and Microsoft integration. Slack wins on everything else. Which matters more depends entirely on what tools your business already runs.
Which one to pick
You're already paying for Microsoft 365 and your team lives in Outlook, Word, and SharePoint. You want strong video conferencing included. You're willing to invest in onboarding the team properly.
Your stack is non-Microsoft or mixed. You want the widest integration library. Your team is remote or async and needs a tool with lower friction. You prioritize interface over video conferencing.
Are you already on Microsoft 365? If yes, Teams is already paid for. The integration with Outlook, SharePoint, and the rest of the suite is genuinely useful and you're not adding a separate line item. Start there.
How many tools does your team connect to daily? If your team uses HubSpot, Jira, GitHub, or a mix of non-Microsoft tools, Slack's 2,600+ integrations will cover your stack better. Teams' 700 integrations cover the basics but have gaps.
Do you need strong video conferencing? Teams. It's built for it. Slack's Huddles work for quick standups but don't replace a proper video meeting tool for client calls or team presentations.
How technical is your team? Teams has a steeper learning curve. For small businesses where everyone onboards themselves, Slack's interface is easier to get running without training. Teams rewards proper IT setup; Slack works better as a self-service tool.
Are you running automations across your tools? Both platforms connect to Zapier and n8n, so you can route notifications from your CRM, project management tool, or job management software into channels either way. The integration depth matters more for which specific tools you're connecting.
Where both tools fall short for small businesses
Teams and Slack are communication tools. They don't automatically route the right information to the right channel when something happens in your business systems.
A new lead coming in through your website, a job completed in Jobber, an invoice paid in QuickBooks, a proposal signed in PandaDoc — none of those events automatically create a Slack or Teams notification unless you build the connection. Most small businesses end up with important updates buried in email or not communicated at all because the tools don't talk to each other.
The automation opportunity is straightforward: a new CRM contact triggers a #leads channel alert, a completed job triggers a #ops update, a signed contract kicks off a #new-client thread. That layer sits between your business tools and your communication platform, and it requires custom automation to build properly.
Running Teams or Slack but your team still finds out about new leads and completed jobs through email or word of mouth? We build the workflows that route the right updates to the right channels automatically.
Get a Free Automation Audit →Other tools worth knowing: Google Workspace, Zoom, and Notion
If you're evaluating Teams and Slack, these three come up often enough to address briefly.
Google Workspace (formerly G Suite) is the strongest alternative to Microsoft 365 for small businesses that want integrated communication and productivity. Gmail, Google Meet, Drive, Docs, Sheets, and Calendar work together in the same way Outlook, Teams, and SharePoint do on the Microsoft side. Google Chat is included but rarely used as a primary communication tool — most Google Workspace teams still end up on Slack for async messaging. If you're choosing between Microsoft 365 and Google Workspace as your base platform, that's a separate decision from Teams vs Slack. Once you've picked your productivity suite, the communication tool choice follows.
Zoom is a video conferencing tool, not a team messaging platform. It doesn't replace Slack or Teams for day-to-day communication. What it does better than both is large-scale video meetings, webinars, and the reliability that comes from a tool built specifically for video. Some businesses run Slack for messaging and Zoom for calls rather than relying on Teams' built-in video or Slack Huddles. That's a reasonable setup if video quality matters more than having fewer tabs open.
Notion is a documentation and knowledge management tool. It overlaps with Teams and Slack only in the sense that all three can host information — but Notion is built for structured, searchable docs and wikis, not real-time messaging. The most common setup we see: Slack for day-to-day communication, Notion for documentation and processes. They're not direct competitors.
Sources
- Microsoft Annual Report, 2023 — Microsoft Teams monthly active users (320 million)
- Microsoft, 2023 — Fortune 500 Microsoft Teams adoption (85%)
- Salesforce/Slack, 2023 — Slack daily active users (38.8 million)
- Salesforce press release, 2021 — Salesforce acquisition of Slack ($27.7 billion)
- McKinsey Global Institute, 2022 — Americans with opportunity to work from home at least part-time (58%)
Your team chat is only as useful as what feeds into it.
Teams and Slack both work. The gap is that most small businesses don't have their CRM, job software, and billing tools routing updates into the right channels automatically. We build that layer.
Frequently asked questions
If you're already on Microsoft 365, Teams is effectively free and integrates deeply with Word, Excel, SharePoint, and Outlook. If you're not on Microsoft 365 or your team uses many non-Microsoft tools, Slack's broader integration library and cleaner interface tend to be the better fit.
Teams has a free plan with limited features. It's also included with Microsoft 365 Business Basic (~$6/user/month) and above. If your business already pays for Microsoft 365, Teams costs nothing extra. Verify current pricing at microsoft.com/microsoft-365.
Slack's free plan limits message history to 90 days and allows 10 integrations. The Pro plan starts at approximately $7.25/user/month (billed annually). Business+ adds SSO and compliance tools. Verify current pricing at slack.com/pricing.
Slack generally has a better reputation for async communication and cleaner channel organization. Teams has better built-in video conferencing. For remote-first teams using many different tools, Slack's integration library tends to be more useful. For teams already in the Microsoft ecosystem, Teams is the more practical choice.
Yes, and some teams do. Slack and Teams can be connected via Zapier or n8n to forward messages between platforms. In practice, running both creates confusion about where conversations happen. Most businesses are better off picking one and routing everything through it.